Highlights from the International Space Development Conference

Conceptual illustration of Mag Mell, a rotating space settlement in the asteroid belt in orbit around Ceres – grand prize winner of the NSS Student Space Settlement Design Contest. Credits: St. Flannan’s College Space Settlement design team*

In this post I summarize a few selected presentations that stood out for me at the National Space Society’s International Space Development Conference 2022 held in Arlington, Virginia May 27-29.

First up is Mag Mel, the grand prize winner of the NSS Student Space Settlement design contest, awarded to a team* of students from St. Flannan’s College in Ireland. This concept caught my eye because it was in part inspired by Pekka Janhunen’s Ceres Megasatellite Space Settlement and leverages Bruce Damer’s SHEPHERD asteroid capture and retrieval system for harvesting building materials.

The title Mag Mell comes from Irish mythology translating to “A delightful or pleasant plain.” These young, bright space enthusiasts designed their space settlement as a pleasant place to live for up to 10,000 people. Each took turns presenting a different aspect of their design to ISDC attendees during the dinner talks on Saturday. I was struck by their optimism for the future and hopeful that they will be representing the next generation of space settlers.

Robotically 3D printed in-situ, Mag Mell would be placed in Ceres equatorial orbit and built using materials mined from that world and other bodies in the Asteroid Belt. The settlement was designed as a rotating half-cut torus with different angular rotation rates for the central hub and outer rim, featuring artificial 1G gravity and an Earth-like atmosphere. Access to the surface of the asteroid would be provided by a space elevator over 1000 km in length.


* St. Flannan’s College Space Settlement design team: Cian Pyne, Jack O’Connor, Adam Downes, Garbhán Monahan, and Naem Haq


Conceptual illustration of a habitat on Mars constructed from self-replicating greenhouses. Credits: GrowMars / Daniel Tompkins

Daniel Tompkins, an agricultural scientist and founder of GrowMars, presented his Expanding Loop concept of self replicating greenhouses which would be 3D printed in situ on the Moon or Mars (or in LEO). The process works by utilizing sunlight and local resources like water and waste CO2 from human respiration to grow algae for food with byproducts of bio-polymers as binders for 3D printing blocks from composite concretes. Tompkins has a plan for a LEO demonstration next year and envisions a facility eventually attached to the International Space Station. He calculates that a 4000kg greenhouse could be fabricated from 1 year of waste CO2 generated by four astronauts. An added bonus is that as the greenhouse expands, an excess of bioplastic output would be produced, enabling additional in-space manufacturing.

Diagram depicting GrowMars Expanding Loop algae growing process to create greenhouse blocks and byproducts such as proteins and fertilizer. Credits: GrowMars / Daniel Tompkins.

Illustration of a portion of the Spacescraper tethered ring from the Atlantis Project. Credits: Phil Swan

Phil Swan introduced the Atlantis Project, an effort to create a permanent tethered ring habitat at the limit of the Earth’s atmosphere, which he calls a Spacescraper.  The structure would be placed on a stayed bearing consisting of two concentric rings magnetically attached and levitated up to 80 km in the air.  In a white paper available on the project’s website, details of the force vectors for levitation of the device, the value proposition and the economic feasibility are described. As discussed during the talk at ISDC, potential applications include:

  • Electromagnetic launch to space
  • Carbon neutral international travel
  • Evacuated tube transit system
  • Astronomical observatories
  • Communication and internet
  • Solar energy collection for electrical power
  • Space tourism
  • High rise real estate

Phil Swan will be coming on The Space Show June 21 to provide more details.


Conceptual illustration of a Mars city design with dual centrifuges for artificial gravity. Credits: Kent Nebergall

Finally, the Chair of the Mars Society Steering committee and founder of MacroInvent Kent Nebergall, gave a presentation on Creating a Space Settlement Cambrian Explosion. That period, 540 million years ago when fossil evidence goes from just multicellular organisms to most of the phyla that exist today in only 10 million years, could be a metaphor for space settlement in our times going from extremely slow progress to a quick expansion via every possible solution. Nebergall suggests that we may be on the verge of a similar growth spurt in space settlement and proposes a roadmap to make it happen this century.

He envisions three settlement eras beginning with development of SpaceX Starship transportation infrastructure transitioning to robust cities on Mars with eventual para-terraforming of that planet. He also has plans for how to overcome some of the most challenging barriers – momentum and money. Stay tuned for more as Kent has agreed to an exclusive interview on this topic in a subsequent post on SSP as well as an appearance on The Space Show July 10th.

NewSpace features the dawn of the age of space resources

Illustration showing concept of operations of the RedWater mining system for water extraction on Mars developed by Honeybee Robotics. Credits: Mellerowicz et al. via New Space

The editorial in the latest issue of New Space, coauthored by two of SSP’s favorite ISRU stars, Kevin Cannon and George Sowers, describes the dawning age of space resource utilization. Cannon, who guest edits this issue, and Sowers are joined by the rest of the leadership team of the graduate program in Space Resources at the The Colorado School of Mines: Program Director Angel Abbud-Madrid and professor Chris Dreyer. The program, created in 2017, has over 120 students currently enrolled. These are the scientists, engineers, economists, entrepreneurs and policymakers that will be leading the economic development of the high frontier, creating the companies and infrastructure for in situ resource utilization that will enable affordable and prosperous space settlement.

How can regolith on the Moon and Mars be refined into useful building materials? What are the methods for extracting water and oxygen from other worlds for life support systems and rocket fuel? Is it legal to do so? Will private property rights be granted through unilateral legislation? What will space settlers eat? The answers to all these questions and more are addressed in this issue, many of the articles free to access.

One of my favorite pieces, the source of this post’s featured image, is on the RedWater system for harvesting water on Mars. This technology, inspired by the proven Rodwell system in use for sourcing drinking water at the south pole, was developed by Honeybee Robotics, just acquired by Blue Origin earlier this year. End-to-end validation of the system under simulated Mars conditions demonstrated that water could be harvested from below an icy subsurface and pumped to a tank up on the surface.

We need to start thinking about these technologies now so that plans are ready for implementation once a reliable, affordable transportation system comes on line in the next few years led by companies such as SpaceX and others. Sowers has been working on thermal ice mining on cold worlds throughout the solar system for some time, predicting that water will be “the oil of space”. Cannon has been featured previously on SSP with his analytical tools related to lunar mining, the Pinwheel Magma Reactor for synthetic geology and plans for feeding millions of people on Mars.

Charon: a reusable single-stage to orbit shuttle for Mars

Conceptual illustration depicting the Charon single-stage to Mars orbit mission architecture. Credits: Jérémie Gaffarel et al.* – image from Graphical Abstract with addition of text.

In the next few decades a settlement on Mars will be established, either by Elon Musk or other spacefaring entities (or both). To enable an economically viable supply chain to support a prosperous colony on Mars, an affordable and sustainable transportation system will be needed. Musk is designing Starship for what he originally called an interplanetary transportation system. But his design is just the first step and is expected to evolve over time. As originally conceived Starship may not make long term economic sense for launch from Earth, travel across interplanetary space, landing on Mars, lift off again and finally, return and safe landing on Earth. Even though the Starship User Guide says the the vehicle is designed to carry more than 100 tons to Mars, the enormous amount of cargo and crew required to be transported to support a prospering and sustainable Martian colony if done only with repeated Starship launches directly from Earth will likely be too expensive.

A better approach might be to limit Starship to an in-space transportation system which cycles back and forth between Earth and Mars orbits without a (Mars) landing capability. Not knowing how Starship may evolve, this could be a starting point. Eventually, a more efficient interplanetary transportation system may be an Aldrin cycler. Either scenario would require a shuttle at Mars for delivery of payloads from low orbit to the surface and back to space again. A team* at Delft University of Technology, The Netherlands has come up with a design for a reusable singe-stage to orbit vehicle they call Charon that would reliably address this final leg of the Mars supply chain. They described the mission architecture in an article in the journal Aerospace last year.

The team identified 80 key design requirements for Charon, but three stood out as the most important. At the top of the list was the capability of transporting 6 people and 1200 kg of cargo to and from low Mars orbit. Next, any consumables needed for the vehicle would have the capability of being produced in situ on Mars. Finally, because of the human rating, the reliability of the system would have to be high – with loss of crew less than 0.5% or 1 out of 270, which is equivalent to SpaceX’s Crew Dragon.

With safety being a high priority an abort subsystem is included to address each anticipated flight phase and the associated abort modes. The SpaceX Starship design does not have an abort system, so the authors believe that Charon would be safer for launch from Mars given the high flight rate anticipated to and from Mars low orbit. They suggest that Starship be limited to launch from Earth and interplanetary transportation to Mars orbit.

Cutaway illustration of the layout of the Charon vehicle adapted from Figure 5 in article. Credits: Jérémie Gaffarel et al.*

Cutaway view of the capsule adapted from Figure 4 in article. Credits: Jérémie Gaffarel et al.*

Significant infrastructure will be needed on Mars to support operations, especially in situ resource utilization for production of methane and oxygen for Charon’s propulsion system. This pushes out the timeline for implementation a few decades (to at least 2050) when a Mars base is expected to be well established with appropriate power sources and equipment to handle mining, propellant manufacturing, maintenance, communications and other needed facilities.

Upon a thorough analysis of Charon’s detailed design, reliability and budgets the team concluded that “The program for its development and deployment is technologically and financially feasible.”

* Gaffarel, Jérémie, Afrasiab Kadhum, Mohammad Fazaeli, Dimitrios Apostolidis, Menno Berger, Lukas Ciunaitis, Wieger Helsdingen, Lasse Landergren, Mateusz Lentner, Jonathan Neeser, Luca Trotta, and Marc Naeije. 2021. “From the Martian Surface to Its Low Orbit in a Reusable Single-Stage Vehicle—Charon” Aerospace 8, no. 6: 153. https://doi.org/10.3390/aerospace8060153

Leveraging Starship for lunar habitats

Conceptual overview of the lunar Rosas Base derived from a SpaceX Starship tipped on its side and covered with regolith. Credits: International Space University, Space Studies Program 2021 Team*. The name of the base is in memory of Oscar Federico Rosas Castillo

SSP has examined some of the implications of SpaceX’s Starship achieving orbit, such as an imminent tipping point in U.S. human spaceflight and launch policy. We’ve also discussed how if its successful, Starship will bring about a paradigm shift in the settlement of Mars and how the spacecraft could be used to determine the gravity prescription.

During Elon Musk’s recent Starship update from Boco Chica, Texas he said that he was “highly confident” that Starship would reach orbit this year. He also predicted that the cost of placing 150 tons in LEO could eventually come down to as low as $10 million per launch, and that “…there are a lot of additional customers that will want to use Starship. I don’t want to steel their thunder. They’re going to want to make their own announcements. This will get a lot of use, a lot of attention….”

“Once we make this work, its an utterly profound breakthrough in access to orbit….the use cases will be hard to imagine.” – Elon Musk

One such potential use case was worked out in detail by a team* of students last year during the International Space University’s (ISU) Space Studies Program 2021 held in Strasbourg, France. Called Solutions for Construction of a Lunar Base, the project used the version of Starship currently under development by SpaceX for the Human Landing System component of NASA’s Artemis Program as the basis for a habitat on the Moon. The concept was also described in a paper at the 72nd International Astronautical Congress in Dubai last October. The mission of the project was:

“To develop a roadmap for the construction of a sustainable, habitable, and permanent lunar base. This will address regulatory and policy frameworks, confront technological and anthropological challenges and empower scientific and commercial lunar activities for the common interest of all humankind.”

The team did an impressive job working out solutions to some of the most challenging issues facing humans living in the harsh lunar environment like radiation, micrometeorites, and hazardous lunar dust. They also dealt with human factors, physiological and medical problems anticipated under these conditions. Finally, the legal aspects as well as a rigorous financial analysis was conducted to support a business plan for the base in the context of a sustainable cislunar economy. The report is lengthy and challenging to summarize but here are some of the highlights.

A decommissioned Starship forms the primary core component of the outpost having its fuel tanks converted to living space of considerable volume. This has precedent in the U.S. space program when NASA modified an S-IVB stage of a Saturn V to create Skylab. The team envisions extensive use of a MOdular RObotic Construction Autonomous System (MOROCAS) outfitted with specific tools to perform a variety of activities autonomously which would reduce the need for extravehicular activities (EVA) thereby minimizing risks to crew. The MOROCAS would be utilized to tip the Starship on its side, pile regolith over the station for radiation protection and a range of other useful functions.

Medical emergencies were considered for accidents anticipated for construction activities in the high risk lunar environment. The types of injuries that could be expected were assessed to inform plans for needed medical equipment and facilities for diagnosis and treatment.

As discussed by SSP in a previous post, hazards from lunar regolith must be mitigated in for any activities on the moon. The solutions proposed included limiting dust inhalation through monitoring and smart scheduling EVAs, the use of dust management systems utilizing electrostatic removal mechanisms and intelligent design of equipment. In addition, landing sites and travel routes would be prepared either through sintering of regolith or compaction to prevent damage to structures by rocket plumes.

Funding of the Rosas Base was envisioned to be implemented via a public/private partnership administered by an international authority called the Rosas Lunar Authority (RLA). The RLA management would be structured as an efficient interface between participating governments while being capable of responding to policy and legal challenges. It would rely on public financing initially but eventually shift to private financing supplemented by rental of the base to stakeholders and interested parties.

Finally the team examined the value proposition driving establishment of the base. Sociocultural benefits, scientific advancements and technology transfer would be the primary driving factors. Initial market opportunities would be targeted at the scientific community in the form of data and lunar samples. Follow-on commercial activities that would attract investors could include launch services to orbit, cislunar spacecraft services, propellent markets in lunar orbit and LEO, communications networks in cislunar space and commercial activities on the surface such as supplies of transportation and mining equipment, habitats, and ISRU facilities.

The surface of the Moon provides exciting opportunities for scientific experimentation, medical research, and commerce in the cislunar economy about to unfold in the next decade. The unique capabilities of Starship and the solutions proposed in this report support a sustainable business model for a permanent outpost like the Rosa Base on the Moon.

Conceptual illustration of an emerging cisluar economy. Credits: International Space University, Space Studies Program 2021 Team*

An executive summary of the project is also available.

__________

* ISU Space Studies Program 2021 participants:

Tube Town – Frontier: Living beneath the surface of the Moon

A lunar sinuous rille (probable collapsed lava tube) Credit: NASA/Lunar Reconnaissance Orbiter (LRO)

SSP featured a post in 2020 on the promise of lava tubes as ideal natural structures on the Moon or Mars in which space settlements could be established. Some are quite voluminous and could contain very large cities. Lava tubes provide excellent protection from radiation, micrometeorite bombardment and temperature extremes while being very ancient and geologically stable.

How would a city be established inside a lava tube? What would it be like to live and work there? Brian P. Dunn paints a scientifically accurate picture of such a future in Tube Town – Frontier, a hard science fiction book visualizing life beneath the surface of the Moon. Dunn recently appeared on The Space Show where he provided tantalizing details on his book scheduled to be published later this year. You can also get a taste of the story through excerpts available on his website.

I’ve had the opportunity to get an advanced copy of his book and will be providing feedback to Dunn prior to publication. He agreed to an interview via email, summarized below, answering some of my initial questions:

SSP: Your first chapter of the book takes place in 2028 and starts out with teleoperated “SciBots” networked together in swarms to explore and prospect for resources at the Moon’s south pole.  They are battery powered and need to periodically recharge at stations at the base of solar power towers at the Peaks of Eternal Light, similar to what Trans Astronautical Corp. is planning with their Sunflower system.  This time frame seems overly optimistic given that NASA’s Artemis program won’t return astronauts to the Moon until the mid 2020s and Jeff Foust reported recently that a second landing won’t take place until 2 years later.  Would it be more realistic to move out the timeline 5-10 years?

BPD: As Kathy Lueders at NASA has said, our strategy with both Moon and Mars is ‘Bots then Boots’. There is much scientific and ISRU work that can be done before the humans arrive. (See the article on my blog “The Mother of All CLPS Missions.”)  With the Moon’s close proximity and communications satellites, we can teleoperate rovers much easier than on Mars. Regarding the SLS/Artemis timeline, I don’t believe it will ever reach full fruition. The Artemis/Gateway architecture is too expensive and too slow. There is a paradigm shift happening now as the concept of large, re-usable, re-fuel able, high payload, quick launch cadence rockets is being proven out with SpaceX’s Starship.

SSP: After discovery of the lava tube in which Tube Town is eventually established, the public “was clamoring for more” and the “excitement of the discovery of the tube breathed new life into lunar and space exploration”.  I know that I would be excited, and most space cadets would be as well, but why would the general public be so supportive of space exploration because of the discovery of a lava tube on the Moon?  A recent poll found that a majority of people think that sending astronauts to the moon or Mars should be either low or not a priority.

BPD: Now that we’re starting to get the rockets, the American public will soon see landers and rovers return to the Moon. This time it will be in HD TV. At some point Americans will return to the Moon. This will be must-see TV. Taikonauts will eventually land on the Moon. This will definitely light a fire under the Americans. Interest in the Moon and lunar exploration will go up. The problem will be sustaining interest (We have an incredibly short attention span). After the world record TV event, interest will wane. We will only be able to put a few astronauts in small habitats on the surface for short periods of time. Upon discovery of an intact lava tube people will know that we could actually build a town on the Moon. Even better than that guy described in that book… what was it called?

SSP: Tube Town is operated by an umbrella organization of national space programs led by NASA called the International Space Program.  How do you envision this cost sharing structure getting started?

BPD: Although much cheaper than a comparable sized surface base, outfitting a lava tube for human habitation will not be cheap. Much of the materials can be made in situ, such as aluminum sheeting for the floors and airlocks, waterless concrete, steel for pressure vessels to hold volatile gasses, but much will need to come from Earth such as Factory machines, computers, electronics, medical equipment, etc.

In Tube Town, this cost is spread among the space programs of 27 countries of the International Space Program (NASA, ESA plus 9 countries that signed the Artemis Accords).

US, Canada, Australia, New Zealand, Japan, South Korea, India, Brazil, Israel, United Arab Emirates, and the 17 member countries of the European Space Agency (Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain Sweden, Switzerland and the United Kingdom). Notable holdouts were China (CNSA) and Russia (Roscosmos).

The ISP is a cost and opportunity sharing umbrella organization for building and maintaining a large Moon base and robotic creation of a Mars base and the first crewed mission to Mars.

NASA would be the lead partner of the ISP, but project decisions were approved and administered by the ISP Board of Directors consisting of the member countries of the organization with weighted voting rights proportionate to their contribution. Many countries wanted to get in on the ground floor of a new space economy but couldn’t afford to duplicate the resources and infrastructure that already existed at NASA. With their combined buying power, the ISP could source rockets, landers, robotics, space suits, etc. from the most efficient and innovative private suppliers. In return, ISP countries received habitation services (shelter, atmosphere, food, water) and discounted rates for:

  • leasing habitation space in the Tube for scientific or commercial enterprise,
  • buying propellant and other in situ resources, and
  • payload return to Earth

ISP construction costs of the Tube are initially off-set by lunar tourism and bespoke mining. Tourism licenses are issued by the ISP to private companies. The contracts include revenue sharing, ISP Code of Conduct compliance and Space Heritage sites preservation requirements. In exchange, the licensees get transportation, medical emergency and habitation services on the Moon.

In Tube Town, the first ISP tourism licensee is with Lunar Experience, LLC. LE licensed 50 seats for a seven Earth day stay. They ran two tours per Earth month to take advantage of the Nearside lunar day (in early days, most of the popular attractions were on the Nearside). LE agreed to give away 25% of the seats to people who could not afford the price. So, of the 50 seats per trip, 12 were free and 38 were paying customers. Assuming a ticket price of $5m for a trip to the Moon for a week, a flight made $190m. The revenue sharing agreement with the ISP was 60/40 (LE 60%, ISP 40%) so for that $190m flight, LE earned $114m and ISP $76m. If only two trips were completed per month, the yearly income would be LE $1.3B and ISP $912m. The ticket price would double to watch the uncrewed launches to Mars and the price would triple to be a part of history to witness the crewed launch to Mars.

In addition, the ISP or commercial customers could take advantage of very reasonable freight rates to backhaul refined payload on the returning tourist rockets to Earth. When would the price become affordable for regular people? Probably after the third tube is discovered. I could see an ISP member like UAE opening a large lava tube exclusively as a vacation resort.

SSP: The main product produced by Tube Town’s factory is spacecraft for Mars exploration and the eventual establishment of an outpost on the Red Planet.  Presumably, at least at first, not all electronic components can be made on the Moon so will have to be imported from Earth via a space-based supply chain.  Elon Musk is designing Starship to go directly to Mars from Earth.  Why does building spacecraft on the Moon for a Mars mission make economic sense when compared to “going direct” like Starship, and why isn’t Starship mentioned in the book? 

BPD: The book is a work of fiction so I try not to use real names or products. Although I think Starship is the first of its class of big, reusable rockets, I also think the concept will be replicated (like airliners) and hopefully there will be several options in the Earth to Moon supply chain. If you can make a big re-usable rocket on a beach in Texas, you can make one inside a nice lava tube on the Moon. We will also need to get lots of bots and machinery to Mars before the humans. This can also be manufactured on the Moon. When you launch, you don’t have to fight the giant gravity well of Earth  (12.6 km/s vs 2.6 km/s) and you may not even have to re-fuel to head for Mars. Huge payloads will be much more economical from the Moon.

Artist conception of a spacecraft manufacturer inside a lava tube. Credit: Riley Dunn

SSP: Tube Town has a Farm devoted to food production, waste re-cycling, and ice processing.  However, without insects or wind pollination it is not possible to grow desirable fruits and vegetables like apples, squash, melons and many more.  You devised an innovative way to pollinate the plants.  Tell us about that!

BPD: Nearly all of the technology described in the book is based on existing technology, whether in the lab or in production. Harvey’s pollinating space bees are based on a combination of miniature drone-delivered soap bubble pollination and AI image recognition software.

SSP: In your book, the Apollo 11 landing site becomes a tourist destination.  What steps are taken to preserve this fragile heritage site?

BPD: I think the Apollo 11 site is the must-see tourist attraction on the Moon. Part of that attraction is that you can still see the boot prints of the astronauts in the regolith. On the moon, boot prints are forever- unless another human destroys them. It only takes one knucklehead.

In my book, a regolith wall is built around the site to protect from plume drift from vehicles. The entrance is a good distance away from the site. Access into the site is in a plexiglass pod that is suspended above the surface. A cable system mounted on tall towers maneuvers pods of tourists through the site from above, giving them a close-up encounter, yet not disturbing the artifacts nor the regolith.

There should be multiple Space Heritage Sites on the Moon consisting of artificial artifacts from multiple countries and natural wonders like Schroter’s Valley. They should be identified and preserved by the tourist licensees that will profit from them.

Vallis Schröteri (Schroter’s Valley), believed to be volcanic in origin, is the largest sinuous rille on the Moon seen here as imaged by Apollo 15. Credits: NASA via Wikipedia

SSP: Tube Town has a centrifuge in the Rec Section to provide artificial gravity for residents to maintain their physical health, but very little detail is provided.  How often do residents use this facility, on average, and is it’s radius optimized to minimize Coriolis forces?  You might consider this well thought out design for a centrifuge.

BPD: I love this design for a lunar lava tube environment! The Rec section of Tube Town is over 400m wide so this is the perfect place for a floor mounted Dorais Gravity Train. In my book, this would be used for scientific study of the effects of artificial gravity treatment in a low gravity environment. They would do studies on both animals, plants and humans. I see crewmembers and tourists using the gravity train as a health spa and treatment against ‘gravity sickness’.

SSP: There are a couple of resident dogs in Tube Town and one them actually becomes pregnant.  This has huge implications for biomedical research on mammalian reproduction in lunar gravity and in particular, determination of the gravity prescription for healthy human gestation.  In my opinion, determination of the gravity prescription is one of the most significant questions to be answered for long term space settlement.  Tell us about how this research is carried out in Tube Town in an ethical manner?

BPD: The studies would start with mice. Only when and if the studies show that mammalian reproduction in low gravity is safe, would the crew move up to higher level mammals. If safe, the female dog would be taken off the canine birth control medication she is on. BTW, all the ISP crewmembers and commercial residents must agree to be on birth control medication while living on the Moon. Many may choose to freeze eggs or sperm on Earth before a long deployment in space.

SSP: Where on the Moon should we look for lava tubes?

BPD: Nearly all of the volcanic activity of the Moon was on the Nearside, not the Farside. So we should definitely concentrate on the Nearside. We can see lots of collapsed lava tubes on the surface of the Moon, the intact ones are probably in the same regions.

Global mosaic map of sinuous rilles identified across the Moon by the LRO Wide Angle Camera. Credits: NASA / D. Hurwitz, J. Head, H. Hiesinger, Planetary and Space Science via Semantics Scholar

My suggestion is to look for them where we would like to find them, in other words, lets look in strategic lunar base locations where there is water and power and easy access to other useful minerals (like metals).

 Multiple sinuous rilles (Aristarchus plateau area) Credit: NASA/LRO

I’m sure NASA knows better than me, but my target priorities would be:

  1. North Pole – because its near water and solar power and metals (the Northern Oceanus Procellarum and the highlands between the maria).
  2. South Pole – because its near water and solar power. The South Pole-Aitken basin is a large impact crater but apparently there was some later volcanic activity so it is possible to find tubes in the South Pole area but they may be smaller in size and length than the ones in the Maria.
  3. Marius Hills (southwest of Schroter’s Valley in Oceanus Procellarum) – because there is lots of volcanic activity and collapsed tubes and it is near minerals and metals.

SSP: Thanks Brian for your exciting vision of our future on the Moon and for the opportunity to get a sneak peek. I’m enjoying the story of Tube Town and wish you much success with the release of the book.

Moon-Mars dumbbell variable gravity research facility in LEO

Conceptual illustration depicting the deployment sequence of a LEO Moon-Mars dumbbell partial gravity facility serviced by SpaceX’s Starship. Left: Starship payloads being moored by a robot arm. Center: 1.6 m ID inflatable airbeams (yellow) play out from spin access and mate with dumbbell end modules. Rectangular solar arrays deploy by hanging at either end as spin is initiated via thrusters at Mars module. Right: Full deployment with Starship and Dragon docked at spin axis hub. Credits: Joe Carroll via The Space Review

There may be no single human factor more important to understand on the road to long term space settlement than determination of the gravity prescription (GRx) for healthy living in less than Earth normal gravity. What do we mean by the GRx? With over 60 years of human space flight experience we still only have two data points for stays longer than a few days to study the effects of gravity on human physiology: microgravity aboard the ISS and data here on the ground. Based on medical research to date, we know that significant problems arise in human health after months of exposure to microgravity. To name a few, osteoporosis, immune system degradation, diminished muscle mass, vision problems due to changes in interocular pressure and cognitive impairment resulting memory loss and lack concentration. Some of these problems can be mitigated with a few hours of daily exercise. But recovery upon return to normal gravity takes considerable time and we don’t know if some of these problems will become irreversible after longer term stays. We have virtually no data on human health at gravity levels of the Moon and Mars, as shown in this graph by Joe Carrol:

Graph of the correlation between human health vs gravity showing the two data points where we have useful data. Whether the relationship is a linear function or something more complex is an unknown of great importance for space settlement. Credits: Joe Carrol presentation at Starship Congress 2019 and Jon Goff post on Selenium Boondocks Nov 29, 2005

The more important question for permanent space settlements is can humans have babies in lower gravity? If we go by the National Space Societies’ definition, an outpost will never really become a permanent space settlement until it is “biologically self-sustaining”. We evolved over millions of years at the bottom Earth’s gravity well. How will amniotic fluid, changes in cell growth, fetal development and human embryos be affected during gestation under lower gravity conditions on the Moon or Mars? There are already indications that problems will arise during mammalian gestation, at least in microgravity as experienced aboard the ISS.

To answer these questions, Joe Carroll suggests the establishment of a crewed artificial gravity research facility in LEO which he described last month in an article in The Space Review. He proposes a Moon-Mars dumbbell with nodes spinning at different rates to simulate gravity on both the Moon and Mars, which covers most of the planetary bodies in the solar system where settlements would be established if not in free space. The facility could be launched and tended by SpaceX’s Starship once the spacecraft is flight worthy in the next few years in parallel with Elon Musk’s plans to establish an outpost on Mars. Musk may even want to fund this facility to inform his long term plans for communities on Mars. If his goal is for the humanity to become a multiplanetary species, surely will want to know if his settlers can have children.

Carroll’s design connects the Moon and Mars modules with radial structures called “airbeams” which will allow crew to access the variable gravity nodes in a shirtsleeve environment. The inflatable members are composed of polymer fiber fabric which can be easily folded for storage in the Starship payload bay. Crews would be initially launched aboard Dragon until the Starship is human rated.

“Eventually, rotating free-space settlements will get massive enough to use other shapes, but dumbbells plus airbeams seem like the key to useful early ones.”

The paper addresses details on key operating concepts, docking procedures, emergency protocols, and the implications for long term settlement in the solar system.

There may even be a market for orbital tourism to experience lower gravity that could make funding for the facility attractive to space venture capitalists, especially if it is located in an equatorial orbit shielded from ionizing radiation by the Earth’s magnetic fields. As the technology matures, older tourists may even want to retire in orbital communities that offer the advantage of lower gravity as their bodies become frail in their golden years.

Humankind’s expansion out into the solar system depends on where we can survive and thrive in a healthy environment. If ethical clinical studies on lower mammals in a Moon/Mars dumbbell clears the way for a healthy life in lunar gravity then we can expand out to the six largest moons including our own plus Mars. If the data shows we need at least Mars gravity, then the Red Planet or even Mercury could be potential sites for permanent settlement. But if nothing below Earth normal gravity is tolerable, especially for mammalian gestation, it may be necessary to build ever larger rotating O’Neillian free space settlements to expand civilization across the solar system. There are vast resources and virtually unlimited energy if we need to do that. But it will take considerable time and careful planning to establish the vast infrastructure needed to build these settlements. If human physiology is constrained by Earth’s gravity then space settlers will want to know this information soon so that the planning process can be integrated into space development activities about to unfold on the Moon and beyond. If Musk finds out that Mars inhabitants cannot have children and wants to establish permanent communities beyond Earth, would he change course and switch to O’Neillian free space settlements?

“If we do need sustained gravity at levels higher than that of Mars, it seems easier to develop sustainable rotating settlements than to terraform any near-1g planet.”

Listen to Joe Carroll answer my questions about his Moon/Mars dumbbell facility from earlier this month on this archived episode of The Space Show.

Starship changes the space settlement paradigm

Artist rendering of an earlier version of Starship (formerly BFR, Interplanetary Transport System) approaching Mars. Credits: SpaceX

A mission architecture for Starship is described in a preprint open access article published online December 2 to be released in the next issue of the New Space Journal. The paper lays out a proposed strategy for using the yet to be validated SpaceX reusable spacecraft to establish a self sustaining colony on Mars. The authors* are a mix of space practitioners from NASA, the space industry and academia. No doubt Elon Musk may be thinking along these lines as he lays his company’s plans to assist the human race in becoming a multi-planet species.

Starship is a game changer. It is being designed from the start to deposit massive payloads on The Red Planet. It will be capable of delivering 100 metric tons of equipment and/or crew to the Martian surface, and after refueling from locally sourced resources, returning to Earth. This capability will not only enable extensive operations on Mars, it will open up the inner solar system to affordable and sustainable colonization.

Some of the assumptions posited for the mission architecture are based on Musk’s own vision for his company’s flagship space vehicle as articulated in the New Space Journal back in 2017, namely that two uncrewed Starships would initially be sent to the surface of Mars with equipment to prepare for a sustainable human presence.

“These first uncrewed Starships should remain on the surface of Mars indefinitely and serve as infrastructure for building up the human base.”

The initial landing sites will be selected based on where the water is. The priority will be finding and characterizing ice deposits so that humans will eventually be able to locally source water for life support and to produce fuel for the trip home. The automated payloads of these initial missions will be mobile platforms similar in design to equipment planned for upcoming robotic missions to the Moon in the next couple of years. One such spacecraft, the Volatiles Investigating Polar Exploration Rover (VIPER) is discussed with its suite of instruments that will be used to assess the composition, distribution, and depth of subsurface ice to inform follow-on ISRU operations.

“The use of water ice for ISRU has been determined as a critical feature of sustainability for a long-term human presence on Mars.”

VIPER Searches for Water Ice on the Moon
Conceptual depiction of the NASA VIPER rover planned for delivery to the Moon’s south pole in late 2023. A mobile platform with a similar suite of instruments based on this design could be launched to Mars aboard Starship. Credits: NASA

To harvest water from subsurface ice the authors suggest using proven technology such as a Rodriguez Well (Rodwell). In use since 1995, a Rodwell has been providing drinking water for the U.S. research station in Antarctica. The U.S. Army Engineer Research and Development Center’s (ERDC) Cold Region Research and Engineering Laboratory (CRREL)  has been working with NASA to prove the technology for use in space in advance of a human outpost on Mars.

Diagram depicting how a Rodriquez Well works. Credits: U.S. Army Engineer Research and Development Center

“Rodwell systems are robust and still in routine use in polar regions on Earth.”

The next order of business is power generation. The authors suggest using solar power as a first choice because the technology readiness level is the most mature at this time. Autonomous deployment of a photovoltaic solar array would be carried out on the initial uncrewed missions. But due to frequent dust storms that could diminish the array reliability, nuclear power may be a more appropriate long term solution once space based nuclear power is proven. NASA’s Glenn Research center is working on Fission Surface Power with plans for a lunar Technology Demonstration Mission in the near future. A solid core nuclear reactor is also an option as the technology is well understood.

These initial missions will robotically assess the Martian environment at the landing sites to inform designs of subsequent equipment to be delivered by crewed Starship missions in future launch windows occurring every 26 months. Weather monitoring will be performed as well as measurements of radiation levels and geomorphology to inform designs of habitats and trafficability. Remotely controlled experiments on hydroponics will also be performed to understand how to produce food. Testing will be needed on excavation, drilling, and construction methods to provide data on how infrastructure for a permanent colony will be robustly designed.

Starship’s ample payload capacity will allow prepositioning of supplies of food and water to support human missions before self sustaining ISRU and agriculture can be established. Communication equipment will be deployed and landing sites prepared for the arrival of people. Much of these activities will be tested on the Moon ahead of a Mars mission.

Production of methane and oxygen in situ on Mars will enable refueling of Starship for the trip home, as envisioned in 1990 by Robert Zubrin and David Baker with their Mars Direct mission architecture. Zubrin’s Pioneer Astronautics may even play a role through provision of equipment for ISRU as they are already working on hardware that could be tested on the Moon soon. One could envision a partnership between Zubrin and Musk as their organizations have common visions, and Zubrin has written about the transformative potential of Starship. When people arrive on Starship during a subsequent launch window after the placement of uncrewed vehicles, further testing of ISRU and life support equipment will be performed with humans in the loop to validate these technologies that will enable Mars settlements to sustain themselves.

If Musk is successful in establishing a permanent self-sustaining colony on Mars will it be a true settlement? The National Space Society in their definition says that a space settlement “..includes where families live on a permanent basis, and…with the goal of becoming…biologically self-sustaining…”, i.e. capable of human reproduction. The definition is agnostic as to if the settlement is in space or on a planetary surface. Musk wants to established cities on the planet housing millions of people by mid century. But does this make sense if settlers can’t have healthy children in the lower gravity of Mars? SSP explored this question in a recent post. Hopefully, once Starship becomes operational, an artificial gravity research facility in LEO will be high on Musk’s priority list to answer this question before he gets too far down the Martian urban planning roadmap. Would he ever consider a change in space settlement strategy in favor of O’Neill type free space colonies? Starship could certainly help facilitate the realization of that vision.

If all goes according to plan, SpaceX will attempt the first orbital flight of a Starship prototype sometime next year, which also happens to be when the next launch window opens up for trips to Mars. Obviously, nothing in rocket development goes according to plan, so the initial flight ready design is at least a year away optimistically. And we know Musk’s timelines are notoriously aspirational. As ambitious as Musk is in driving his company toward the goal of colonizing Mars, it seems unlikely that an initial uncrewed mission with all its flight ready automated hardware as described above could be ready by the next launch window in 2024. But what about 2026? NASA’s current plans for return to the Moon call for a human rated version of Starship as a lunar lander “…no earlier then 2025”. However, Japanese billionaire Yusaku Maezawathe’s Dear Moon mission sending 8 crew members around Luna with a crewed Starship is still planned for 2023. A lot of details are yet to be worked out and we still have not covered the topic of Planetary Protection nor the granting of a launch license to SpaceX by the FAA, but could a Starship human mission to Mars take place in 2028? Let me know what you think.

“The SpaceX Starship vehicle fundamentally changes the paradigm for human exploration of space and enables humans to develop into a multi-planet species.”

* Authors of Mission Architecture Using the SpaceX Starship Vehicle to Enable a Sustained Human Presence on Mars Jennifer L. Heldmann, Margarita M. Marinova, Darlene S.S. Lim, David Wilson, Peter Carrato, Keith Kennedy, Ann Esbeck, Tony Anthony Colaprete, Rick C. Elphic, Janine Captain, Kris Zacny, Leo Stolov, Boleslaw Mellerowicz, Joseph Palmowski, Ali M. Bramson, Nathaniel Putzig, Gareth Morgan, Hanna Sizemore, and Josh Coyan

Interview with Mikhail Shubov: Guided self replicating factories, orbital fuel depots, hydrogen production on Mars and other visions for space settlement

Vintage 1980 artist depiction of a self replicating factory on the Moon. Credits: NASA

Earlier this year SSP covered self replicating factories for space settlement. An innovative paper on this topic with a simpler approach was submitted by Mikhail Shubov to ArXiv.org in August that shows how to accelerate efforts in this area.

A fully autonomous self replicating factory in space requires significant advancements in artificial intelligence, robotics, and other fields. Such facilities are mainly theoretical at this point and may not be feasible for many decades. But if humans could “guide” the operation remotely via computer control, a colony on the Moon could be started relatively soon.  This could be the proving ground for establishing such facilities on other worlds which Shubov believes could be set up on Mercury, Mars and in the Asteroid Belt eventually leading to exponential growth allowing humanity to expand out into the solar system and beyond.  He suggests that rather then using the usual definition of self-replication in which a factory would make a duplicate copy of itself, until this capability is realized, a better figure of merit would be the “doubling time”. This is how long it takes to double the facility’s mass, energy production, and machine production.

I reached out to Dr. Shubov about this article and discovered that he has been busy with a variety of scholarly papers on several technologies needed for space settlement. He agreed to a wide ranging interview via email about these topics and his vision of our future in space.

SSP: Thank you Dr. Shubov for taking the time for this interview.  With respect to your work on Guided Self Replicating Factories (GSRF), there are already companies developing semiautonomous robots for in situ resource utilization on other worlds.   OffWorld, Inc. states that “We envision millions of smart robots working under human supervision on and offworld, turning the inner solar system into a better, gentler, greener place for life and civilization.”  Their business model is focused on developing a robotics platform for mining and construction on Earth, then leveraging the technology for use in space.  Do you think this is a good approach to get started?

MS: Thank you Mr. John Jossy for taking interest in my work!

In my opinion, remotely guided robots will be very effective for construction of a colony on the Moon. These robots could be guided by thousands of remote operators on Earth. They would be linked to Earth’s Internet via Starlink which is already being deployed by Elon Musk via SpaceX. Starlink will consist of thousands of satellites linked by lasers and providing broadband Internet on Earth. About 1,646 satellites are already orbiting the Earth.

Hopefully, it would be possible to produce [an] Earth-Moon Internet Connection of about a Terabit per second. That would enable people on Earth to remotely operate hundreds of thousands of robots.

Using these robots on Asteroids and other planets of Solar System will be much more difficult due to low bandwidth and high delay of communication. For example, latency of communication between Earth and Mars is 4 to 21 minutes.

SSP: Obviously, establishing outposts on other worlds where astronauts could teleoperate robots to build a GSRF would eliminate the latency problem, which you address in your paper.

You’ve envisioned four elements of a GSRF: an electric power plant, a material production system (ore mining, beneficiation, smelting), an assembly system in which factory parts are shaped and fabricated, and a space transportation system.  With respect to the space transportation system you cover both launch vehicles and in-space propulsion systems.  The space transportation element of a GSRF, although vital for its implementation, seems to be an external part of the system.  In fact, you stated that “Initially, spaceships will be built on Earth. Fuel for refueling spaceships will be produced in space colonies from the beginning.”  So, when calculating the doubling time of a GSRF, we are not including the production of space transportation systems, correct?

MS: In my opinion, [the] space transportation system may become part of GSRF at later stages of development. How soon space transportation becomes a part of GSRF depends on the speed of development of different technologies.

If inexpensive space launch from Earth becomes available, then there will be less reliance on self-replication and more reliance on transportation of materials from Earth. In this case, space transportation system will not be part of GSRF for a long time.

If rapid growth of a Space Colony by utilization of in situ resources is possible, then many elements of space transportation system would be produced at the colony. In this case, [the] space transportation system will become a part of GSRF relatively soon.

SSP: You suggest that an important product produced by a GSRF in the Asteroid Belt would be platinum group metals to be delivered to Earth, and that they would help finance expansion of space colonization.  Some space resource experts, including John C. Lewis, believe that “…there is so vast a supply of platinum-group elements in the NEA [Near Earth Asteroids] … that exploiting even a tiny fraction of them would cause the market value to crash, bringing to an end the economic incentive to mine and import them.”  Some suggest the market for these precious metals may be in space not on Earth.  When you say “delivered to Earth” what markets were you envisioning to generate the profits needed to finance the GSRF?

MS: In my opinion the main applications of platinum group metals would be in industry. First, PGM are very important as chemical reaction catalysts. In particular, platinum is used in hydrogen fuel cells and iridium is a catalyst in electrolytic cells. It is likely that demand for platinum, iridium and other PGM will grow along with hydrogen economy. Second, platinum and palladium is used in glass fiber production.

Third, Iridium-coated rhenium rocket thrusters have outstanding performance and reusability. Rhenium is also used in jet engines. These thrusters will also provide a market for iridium and rhenium metals.

SSP: As the need for PGM grows exponentially in the future, especially with energy and battery production needs on Earth in the near future, the environmental impacts of mining these materials on Earth may be another reason to source these materials off world.

Mining water to produce hydrogen for rocket fuel is a theme throughout your writings.  In a paper submitted to the arXix.org server last month entitled Feasibility Study For Hydrogen Producing Colony on Mars, you propose that a technologically mature Martian factory could produce and deliver at least 1 million tons of liquid hydrogen per year to Low Earth Orbit.  Does placing a hydrogen production facility on Mars for fuel used in near-Earth space make sense from a delta-v perspective?  You acknowledge that initially it will be cheaper and easier to access the Moon’s polar ice to produce hydrogen.  But in the long term, Near Earth Asteroids (NEA) or even the Asteroid Belt are easier to access and they include CI Group carbonaceous chondrites which contain a high percentage (22%) of water.  Can you reconcile the economics of sourcing hydrogen on Mars over NEAs?

MS: Delivery of Martian hydrogen into the vicinity of Earth may be necessary only when the space transportation technology is relatively mature. In particular, as I mention in my work, Lunar ice caps contain between 48 million and 73 million tons of easily accessible hydrogen. Until at least 16 million tons of Lunar hydrogen is used, hydrogen from other sources would not be needed.

As I calculate in my work, delta-v for transporting hydrogen from Low Mars Orbit to LEO is 3.5 km/s accomplished by rocket engines plus about 3.2 km/s accomplished by aerobreaking. This would be economic if vast amounts of electric energy will be produced on Mars easier than on asteroids. An important and renewable resource on Mars is the heat sink in the form of dry ice. This may enable production of vast amounts of electric energy by nuclear power plants.

Even if delivery of hydrogen from Low Mars Orbit to Earth turns out to be economically infeasible, hydrogen depots in near-Mars deep space would still play a very important role in transportation to and from Asteroid Belt as well as [the] Outer Solar System.

SSP: Your first choice of a power source for the colony on Mars is an innovative heat engine utilizing dry ice harvested from the vast cold reservoirs at the planet’s polar caps. You suggest that the initial heat source for this sublimation engine be a nuclear reactor. Why not simply use the nuclear reactor to produce electricity? Nuclear reactors coupled to high efficiency Stirling engines for electricity generation like NASA’s Kilopower project have very high power density per unit weight and the technology will be relatively mature soon. Your second choices are solar and wind which are not as reliable as a nuclear power source, especially with reduced solar flux at Mars’s orbit and the problem caused by dust in the atmosphere. Why was a more mature nuclear power technology for direct electricity production not considered?

MS: Thank you.  As I understand now, a regular nuclear reactor with a heat engine using water or ammonia as a working fluid is the best choice for energy production on Mars.  Dry ice should only be used as a heat sink and not as working fluid.  Given the very low temperature and ambient pressure of Martian dry ice, it is likely that power plants will have thermal efficiency of at least 50%.

Almost all components of Martian power stations can be manufactured from in situ resources.  Only the reactors themselves and the nuclear fuel will have to be delivered from Earth.

SSP: A booming space transportation economy will need cryogenic fuel depots to store hydrogen for rocket fuel in strategic locations throughout the inner solar system.  You’ve got this covered in your recent paper Hydrogen Fuel Depot in Space.  Some start ups like Orbit Fab have already started work in this area, albeit on a smaller scale, and United Launch Alliance integrated cryogenic storage into their Cislunar-1000 plans a few years back, but this initiative seems to have slowed down due to delays in ULA’s next generation Vulcan launch vehicle.  In this paper you calculate the required energy to refrigerate hydrogen in one smaller (400 tons) and another larger (40,000 tons) depot.  In both cases, a sun shield is required to block sunlight to prevent boil off.  You don’t mention the method of power generation to provide energy for the refrigeration units.  Could the sun shield have a dual use function by incorporating photovoltaic solar cells on the sun facing side to generate electricity to power the refrigeration system?

Diagram depicting a cryogenic liquid hydrogen storage depot with 40,000 ton capacity. Credits: Mikhail Shubov

MS: Power for the refrigeration system will be provided by an array of solar cells placed on the sun shield.  As I mention in my work, the 400 ton depot requires 80 kW electric power for the refrigeration system, while the 40,000 ton depot requires 840 kW electric power.  This power can be easily provided by photovoltaic arrays.

SSP: SpaceX has proven what was once believed impossible: that rockets could be reused and that turnaround times and reliability could approach airline type operations.  Although we are not there yet, costs continue to come down.  In your paper entitled Feasibility Study For Multiply Reusable Space Launch System you calculate that with your proposed system in which the first two stages are reusable and the third stage engine can be returned from orbit, launch costs could be reduced to $300/kg.  Musk is claiming that with the projected long term flight cadence, eventually Starship costs could be as low as $10/kg.  Even if he is off by a factor of 10 that is still lower than your figure.  What advantages does your system offer over Starship? 

MS: The main advantage of the Multiply Reusable Space Launch System is the relatively light load placed on each stage. As I mention on p. 10, the first stage has delta-v of 2.6 km/s and the second stage has delta-v of 1.85 km/s. The engines have high fuel to oxidizer ratio and a low combustion chamber temperature of 2,100oC. These relatively light loads on the rocket airframes and engines should make these rockets multiply reusable similar to airliners. The launch system should be able to perform about 300 space deliveries per year.

Hopefully Elon Musk would succeed [in] reducing launch costs to at least $100 per kg. Unfortunately, many previous attempts at drastic reduction of launch costs did not succeed. Hence, we may not be sure of Starship’s success yet.

SSP: You state in several of your papers that:

“A civilization encompassing the whole Solar System would be able to support a population of 10 quadrillion people at material living standards vastly superior to those in USA 2020. Colonization of the Solar System will be an extraordinary important step for Humankind.”

Why do you think that colonization of the solar system is important for humanity and when do you think the first permanent settlement will be established on the Moon or in free space?  Here I use the National Space Society’s definition of a space settlement:

“A space settlement” refers to a habitation in space or on a celestial body where families live on a permanent basis, and that engages in commercial activity which enables the settlement to grow over time, with the goal of becoming economically and biologically self-sustaining as a part of a larger network of space settlements. “Space settlement” refers to the creation of that larger network of space settlements.

MS: In my opinion colonization of Solar System will bring unlimited resources and material prosperity to Humankind.   The human population itself will be able to grow by the factor of a million without putting a strain on the available resources.

As for the time-frame of establishment of human settlements on the Moon and outer space, I have both optimistic and pessimistic thoughts.  On one hand, Humankind already possesses technology needed to establish rapidly growing space settlements.  This means that Solar System colonization can start at any time. On the other hand, such technology already existed in 1970s.  This technology is discussed in Gerard K. O’Neill’s 1976 book “The High Frontier: Human Colonies in Space”.  Thus, space colonization can be indefinitely delayed by the lack of political will.  Hopefully space colonization will start sooner rather then later.

Credits: Gerard K. O’Neill / Space Studies Institute Press

Coming soon: the $10M orbital condominium

Living space in a Kalpana orbital space settlement. Credits: Bryan Versteeg

Kasper Kubica presents an optimistic business case for space tenants moving in (er, up) to deluxe condominiums orbiting the Earth within 10 years. Initially for the ultra rich, the price tag is comparable to high end real estate currently on the market. Of course the devil is in the details, so lets dive in.

In a post on Medium, Kubica uses the rotating habitat Kalpana as an illustrative example of his “Spacelife Direct” approach for an orbital settlement spinning to create 1G of artificial gravity and hosting north of 400 condominiums in LEO. Such a facility would be shielded from radiation by Earth’s magnetosphere if it were located in low equatorial orbit and therefore could be constructed with less shielding. This results in a significant reduction of mass driving costs way down. Running the numbers on this scenario opens up exciting possibilities with the amazing capabilities of Elon Musk’s Starship currently under development by SpaceX.

Using the scaled down Kalpana Two version as discussed in Tom Marotta and Al Globus’ book, The High Frontier, an Easier Way, the cylindrical habitat is sized at just over 100 meters in diameter and the same in length, weighing in at 16, 800 metric tons. Kubica estimates that it would take 140 launches to loft the required mass to LEO. Assuming costs keep coming down as Starship launch cadence increases (a safe bet), at $10M/launch the cost of just the materials to LEO would be $1.4B. Of course there are many more expenses associated with design, development and fabrication, not to mention insurance of such an orbital condo complex. For the sake of argument Kubica triples that figure arriving at a total price tag of $4.2B.

But would there be a market for real estate in LEO? Kubica provides comparable examples of skyscrapers with similar costs and over 200 condominiums recently selling for over $10M in Manhattan.

“The clamor for earthside luxury condos is massive and growing. Orbital condos — representing an exclusive experience far beyond that available to anyone on earth — could generate astronomical demand.”

With the economics of Starship opening up limitless possibilities, Kubica lays out a roadmap over the next 10 years to realize the Spacelife Direct opportunity. First would come financing the venture though a team of visionary entrepreneurs and investors (are you listening Dylan Taylor?). Design and development would come next including the robotic systems that would be required for assembly in space. Laying the groundwork for this infrastructure may be completed soon by Orbital Assembly Corporation which could potentially be leveraged as a Spacelife Direct supplier. To keep labor costs down much of the facility would be fabricated on Earth in launchable modules that would be assembled in orbit. The final stages would activate life support systems and finish out the interiors for the occupants to begin moving in.

So what about the rest of us? As history has shown in the aerospace industry at the beginning of the last century and we see unfolding in the space tourism market today, the rich help pave the way so that mass production and economies of scale will drive down costs eventually making space settlement affordable for the masses.

“We don’t want to live in space because it’s an economic necessity, we want to live in space because we are explorers and adventurers, and space is humanity’s next frontier!”

Are we close to a tipping point for human spaceflight?

Artist depiction of Starship on the lunar surface returning astronauts to the Moon as part of NASA’s Artemis Program. Credits: SpaceX

What will be the impact on the direction of U.S. space policy should SpaceX successfully demonstrate an orbital flight of Starship? Doug Plata, President and Founder of the Space Development Network believes that when Starship achieves orbit, policy makers should “…place Starship at the center of the country’s human spaceflight program…”. In an article in The Space Review he makes the case that if successful in its efforts, SpaceX may be edging us closer to a tipping point on deciding which path to take for the country’s human rated launch vehicle: Space Launch System (SLS) or Starship? This question is accentuated by recent news reports of yet another delay in the Artemis 1 uncrewed test flight of SLS which Ars Technica reports may not launch until the summer of 2022…assuming everything goes perfectly. Meanwhile, SpaceX continues its development of Starship at a breakneck pace, while simultaneously building the manufacturing infrastructure to “…crank them out by the hundreds”, says Plata. With the delay of Artemis 1, it is possible that SpaceX will demonstrate the first orbital launch of Starship before NASA’s first launch of SLS.

NASA has already selected SpaceX to return astronauts to the Moon via Starship as the Human Landing System for the Artemis program, although work has stalled on the contract due to Blue Origin’s lawsuit. But with a reusable Starship at a fraction of the cost, comparable heavy lift capability and a much higher flight rate, how long can SLS last? A case could be made for keeping SLS until SpaceX’s Super Heavy booster is human rated and Starship can be reliably shown to reenter the Earth’s atmosphere and land safely. But this won’t be long given Elon Musk’s aggressive timelines. Will it continue to make sense to launch astronauts on SLS/Orion, transfer them to Starship in lunar orbit and descend to the surface of the Moon when the the whole mission could be accomplished without SLS at a fraction of the cost?

“At some point, it will be obvious that SLS is an unnecessarily expensive alternative to Starship”

With Starship’s anticipated payload capabilities of delivery of 100s of tons and large crews to the lunar surface, and recent advances in inflatable technology, a habitat with a footprint of about 21,000 sq. ft. is within reach. Plata believes that the billions of dollars slated for SLS would be better spent contracting with SpaceX for delivery of inflatables and their supporting infrastructure to the lunar surface. This could lead to a large international lunar base which may eventually become a permanent settlement.

Instabase
Conceptual illustration of InstaBase – a fully inflatable lunar base capable of supporting an initial crew of eight. Credits: The Space Development Network via The Space Review

“But there is an important historic significance to Starship as well…the real historic prize to be seized is the establishment of humanity’s first foothold off Earth.”